Field of Invention
The present invention relates to a mixing machine, and more particularly to a method and system of stirring liquid form material, such as raw material of frozen product, for creating a radial stirring vortex to efficiently stirring the liquid material in a chilling container.
Description of Related Arts
A mixing machine, such as an ice cream making machine, generally comprises a stirrer disposed in a chilling container for stirring liquid material therein. A conventional stirrer comprises a rotatable shaft being driven to rotate by a motor and a plurality of flat blades or helical blades radially extended from the rotatable shaft, such that when the rotatable shaft is rotated, the stirrer creates a vertical vortex within the chilling container. For example, the stirrer in the ice cream making machine will mix the raw liquid material to make the finished ice cream. It is worth mentioning that the vertical vortex has a center defined at the rotatable shaft and a diameter gradually increasing from bottom to top, such that the liquid material is whirled to be pushed from the bottom of the chilling container to the top thereof. However, the major drawback of the vertical vortex is that only the liquid material at the bottom-center portion of the chilling container will be whirled. In other words, the vertical vortex cannot effectively whirl the liquid material at the bottom-peripheral portion of the chilling container. In fact, the liquid material will gradually precipitate and remain at the bottom-peripheral portion of the chilling container. Since the liquid material is viscous, the liquid material will become more thicker and sticker at the bottom-peripheral portion of the chilling container. On the other hand, the velocity of the vertical vortex can be increased to enlarge the diameter coverage of the vertical vortex for reaching the liquid material at the bottom-peripheral portion of the chilling container. However, the upward pushing force of the vertical vortex will also be increased to push the liquid material from the bottom of the chilling container to the top thereof. The increasing upward pushing force will cause the liquid material to spill out of the chilling container. In other words, a deeper chilling container is needed. As a result, the size of the stirrer, the velocity of the stirrer, and the size of the chilling container must be well-configured corresponding to the volume of the liquid material.
A need exists for a stirrer that creates a radial stirring vortex to efficiently stirring the liquid material in the chilling container. It is to the provision of such a stirrer that the present disclosure is primarily directed.